Comparison of the 2-step tuberculin skin test and the quantiFERON-TB gold in-tube test for the screening of tuberculosis infection before liver transplantation

Abstract

The ability of interferon-c release assays (IGRAs) to detect latent tuberculosis (TB) infection before liver transplantation (LT) is not well established. The aims of this study were (1) to compare the ability of the tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-IT) test (a whole-blood IGRA) to diagnose latent TB infections in patients awaiting LT and (2) to correlate the results with the severity of liver disease. We conducted a prospective, cross-sectional study of patients who were evaluated for LT between July 2008 and July 2010. The 95 patients who were included underwent the 2-step TST and the QFT-IT test. The mean Model for End-Stage Liver Disease (MELD) score was 13.8. Forty-four patients (46.3%) had positive TST results, 42 (44.2%) had positive QFT-IT results, and 2 (2.1%) had indeterminate QFT-IT results. Simultaneous TST and QFT-IT testing yielded a positivity rate of 55.8% [95% confidence interval (CI) ¼ 45.3-65.9] with either test, and the 2-step TST yielded a positivity rate of 46.3% (95% CI ¼ 36.1-56.8); the difference was 9.5% (P ¼ 0.004). In an adjusted analysis, the rates for positive TST results were lower in patients with MELD scores !18 [odds ratio (OR) ¼ 0.2, 95% CI ¼ 0.04-0.7], lower in Child-Pugh-Turcotte (CPT) class C patients versus CPT class A patients (OR ¼ 0.1, 95% CI ¼ 0.02-0.6), and higher in males (OR ¼ 6.4, 95% CI ¼ 1.9-22.0). In contrast, only being male (OR ¼ 3.5, 95% CI ¼ 1.1-11.0) was associated with positive QFT-IT results; no association was found with the MELD score (OR ¼ 0.8, 95% CI ¼ 0.2-2.8) or the CPT class (OR ¼ 0.3; 0.05-1.4). In conclusion, the QFT-IT test is better than the TST for detecting latent TB infection in patients with more advanced liver disease. Our results support the regular use of the QFT-IT test for screening patients with end-stage liver disease for latent TB infection before LT. Liver

Clinical features and outcomes of tuberculosis in transplant recipients as compared with the general population: a retrospective matched cohort study

“…Moreover, the TST failed to detect tuberculosis in any TR with active infection, although it was positive in >80% of patients from the general population. Some studies have suggested that interferon-γ release assays are more sensitive than the TST in transplant candidates and TRs [33][34][35][36]. Unfortunately, neither of the tests is infallible in diagnosing M. tuberculosis infection, or distinguishes between active and latent tuberculosis [13,14,19,37].…”

High rates of indeterminate interferon‐gamma release assays for the diagnosis of latent tuberculosis infection in liver transplantation candidates

“…A number of significant limitations are associated with use of TSTs. Firstly, lower sensitivity for TB detection in severe liver disease is reported, with anergic responses recording falsely negative test results . Other concerns include poorer test specificity in patients with prior BCG vaccination or atypical mycobacteria, inconvenience related to requirement for two visits by specialist nurse, and less objective and standardized reporting.…”

Tuberculosis in solid organ transplant candidates and recipients

“…A few studies on transplant candidates have shown some advantage of IGRA over TST. In a study on 95 patients in Spain awaiting liver transplant, the results of positive TST were lower with increasing Model for End-Stage Liver Disease score (18) and more advanced Child-Pugh-Turcotte Class (C versus A) of liver disease [13]. As the QFT-IT test positivity showed no association with stage of liver disease, the authors concluded that QFT-IT test is superior to TST for LTBI detection in patients with advanced liver disease.…”